The present invention relates to a substrate cassette to be stored or transported with substrates loaded at spaced positions therein.
Various kinds of substrates including glass substrates for LCDs (Liquid Crystal Displays), plasma displays, hybrid ICs (Integrated Circuits) and thermal heads are extensively used. These kinds of substrates are loaded in a substrate cassette for storage or transport. The prerequisite with the substrate cassette is that substrates accommodated therein be prevented from contacting each other. To meet this requirement, it has been customary to form shelves facing each other on a pair of grooved side plates in the form of comb teeth. Each substrates each is inserted in the grooves of the side plates facing each other.
Japanese Patent Laid-Open Publication Nos. 5-147680 and 6-191547, for example, each discloses a box-like substrate cassette of the kind sustaining only opposite end faces of a substrate. This, however, brings about a problem that the substrate is dislocated horizontally or moved vertically during transport. When the substrate is moved horizontally or vertically, friction acts between the end faces of the substrate and the surfaces of the side plates and produces dust which causes troubles in circuitry formed on the substrate.
Today, there is an increasing demand for a thin, large size substrate configuration. Glass substrates, for example, having the conventional thickness of 1.1 mm and thicknesses as small as 0.7 mm to 0.5 mm are in use. As for size, glass substrates as broad as 400.times.500 mm or even 550.times.650 mm, which is approximately twice the conventional size of 370.times.470 mm, are available. Under these circumstances, the substrates are easy to deform and apt to break due to a fall during handling or due to contact with a robot hand.
Technologies relating to the present invention are also disclosed in, e.g., Japanese Patent Laid-Open Publication No. 4-139741.